Most delivery vehicles have a cargo box which is covered in order to protect the cargo against loss due to theft or exposure to weather. The cover over the cargo box is not always of sufficient height to permit a man to stand. For example, half ton trucks equipped with low covers commonly called "shells" are often used as delivery vehicles. This means that the delivery man must risk injury to himself by carrying cargo while bent over, or risk damage to the cargo by dragging it across the cargo box.